The Transient Receptor Potential Vanilloid 1 (TRPV1) plays a pivotal role in the development of post-inflammatory hyperalgesia; thus, TRPV1 ligands could be clinically useful as analgesic and anti-inflammatory drugs.
Compounds deriving from natural products and referred to as capsaicinoids and resiniferonoids are known TRPV1 ligands. Among them, retvanil, the vanillamide of retinoic acid, is a potent agonist1
Ber. der Deutschen Chem. Gesellschaft, vol. 70, pp. 1009-1012 discloses the synthesis of the following compounds:

but it does not mention their biological properties.
WO 03/024920 mentions the use of retinoids for the treatment of arthritis and inflammatory dermatological disorders.
Chem. Pharm. Bull. 43(1) 100-107 (1995) discloses, in particular, the following compounds:

wherein R is hydrogen and R′ is hydrogen or methyl and their retinoidal activity.
WO 03/049702, JOC vol. 48, no. 1, 2005, pp. 71-90 and Neuropharmacology, vol. 46, no. 1, 2004, pp. 133-149 disclose N-aryl cinnamides containing a mojety which can be represented as follows:

wherein A is substituted aryl. These compounds are antagonists of the vanilloid receptor and can be used for the treatment of a number of inflammatory conditions.